What is the characteristics of slewing bearing materials?

Aug 25, 2021

Slewing bearing is mainly composed of rings, rolling body, cage, sealing ring and so on. Different parts have special functions in practical application, they have different considerations in the design of materials.

Generally, the rolling body of slewing bearing is made of integrally hardened carbon chromium bearing steel. The slewing bearing ring is made of surface hardened steel. When the user has no special requirements, it is generally made of 50Mn steel. But sometimes, in order to meet the needs of some special application occasions, other grades of surface hardened steel, such as 42CrMo and 5CrMnMo, can also be selected according to the specific conditions provided by the user.

Circular or square bar is used as billet for small and medium sized slewing ring bearing forgings. The grain structure and mechanical properties of the bar are uniform and good, the shape and size are accurate, the surface quality is good, and it is easy to organize mass production. As long as the heating temperature and deformation conditions are reasonably controlled, the forging with good performance can be forged without large forging deformation. Ingots are only used for large forgings. The ingot is a cast structure with large columnar crystals and loose cores. Therefore, the columnar grains must be broken into fine grains through large plastic deformation, and then the loose and compacting can obtain excellent metal structure and mechanical properties.

The cage for slewing bearing has integral type, segment type, isolation block type and other structure forms. The integral and sectional cages are made of No. 20 steel or ZL102 cast aluminum alloy. The isolation block is made of polyamide 1010 resin and ZL102 cast aluminum alloy. With the development of material industry, nylon GRPA66.25 has been widely used in the design of sectional cage.

The sealing ring of slewing bearing is made of oil-resistant butadiene rubber. The code of the supply state of the ferrule material and the blank is specified in the table. In the table, "T" means that the ferrule is supplied in the condition of quenching and quenching, and "Z" means that the ferrule is supplied in the condition of normalizing.